Add commands for new posts and publishing to readme

These sections should be fleshed out better, but for the time being,
this will help people contribute.

Change-Id: I5d8be00cc7a1d6ce6d6f26f0f1aeba2635d3b03e
Reviewed-on: https://gerrit.causes.com/22968
Reviewed-by: Ben Wiseley <ben.wiseley@causes.com>
Reviewed-by: Aiden Scandella <aiden@causes.com>
Reviewed-by: Greg Hurrell <greg@causes.com>
Tested-by: Joe Lencioni <joe.lencioni@causes.com>